Involvement of peripheral nervous system in juvenile Parkinson's disease.

We evaluated, by using electrophysiological techniques, 29 patients with juvenile Parkinson's disease (JP), who had no known causes or clinical signs of neuropathy. Electromyographic evidence of chronic partial denervation with reinnervation was observed in nine patients (34.6%). Abnormalities of motor conduction in the common peroneal nerve were present in four (13.8%), Sural sensory conduction in nine (31.9%) and sympathetic skin response (SSR) in eleven (37.9%) patients. The symptoms of dysautonomia correlated poorly with changes in SSR. These abnormalities were independent of age at onset, duration or severity of the disease and antiparkinsonian drugs used. This study suggests that the peripheral nervous system is involved in JP in more than 50% of patients. The commonly observed symptoms of dysautonomia in Parkinson's disease may have a peripheral origin.